Incandescent electric lamp.



W. L. BARNARD.

INCANDESCENT ELECTRIC LAMP.

APPLICATION FAILED IAN-29,1917.

1,273,130. Patented July 23,1918

2 SHEET'SFSHEET 1.

'w. L. BAYRNARD. NCANDESCENT ELECTRIC LAMP. APPLICATION FILED JAN.29,1917.

1,273,130. Patente'dJuly 23,191&

2 SHEETS-SHEET 2- WILLIAM L. BARNARD, OF ST. LOUIS, MISSOURI.

IN CANDESGENT ELECTRIC LAMP.

Specification of Letters Patent.

Patented July 23, 1918.

Application filed January 29, 1917. Serial No. 145,173.

To all whom it may concern Be it known that I, WILLIAM L. BARNARD, a citizen of the United States, and resident of St. Louis, Missouri, have invented certain new and useful Improvements in Incandescent Electric Lamps, of which the following is a specification containing a full, clear, and exact description, reference being had to the accompanying drawings, forming a part hereof.

My invention relates to improvements in incandescent electric lamps, wherein a number of filaments in a single lamp or source of light are associated with a rotary switch in a manner to produce continuous uniform luminosity as to the group of filaments, but intermittent luminosity as to the individual filaments whereby luminosity in a single source of light is attained without the usual attendant heat radiation.

My object is to construct an incandescent electric lamp, having a number of filaments which are individually connected with a switch in a manner to energize a certain filament while the remaining filaments are radiating heat following their energization whereby to obtain a relatively increased candle power with a lesser current consumption and with no appreciable heat radiation, from the lamp as a whole.

In the following specification 1 will fully, clearly and concisely set forth my improvements, definitely point out the same in my claim and illustrate one embodiment thereof in my drawings, in which Figure 1 is asectional elevation of a lamp and switch constructed according to my invention.

Fig. 2 is a sectional plan of the lamp, taken on the line 22 of Fig. 1, and

Fig. 3 is a diagram showing the wiring relating the filaments to the switch.

Referring to the accompanying drawings by numerals, I employ the numeral 5 to designate the bulb which is made of transparent material, preferably glass, and has integrally formed therewith and extended thereinto a single element consisting of a neck 6, a head 7 and a stem 8. The. stem 8 has extended therethrough and projecting beyond its inner end a conductor 9 which has connected therewith both mechanically and electrically, a spider 10 and connected with each arm of the spider there is a filament 11.

The head 7 is provided with nipples corresponding in number and disposition with the arms of the spider and extended through the neck 6 through the head 7 and through the nipples are the conductors 12, each of which connects with a filament 11. The bulb is of the type which is hermetically sealed and a vacuum formed therein as is common, and by preference is arranged to be secured in a fixture comprising a socket 13, and further by preference the conductor 9 is electrically connected with the socket and the socket connected by means of a wire 1-1 with a source of electrical energy not shown.

Each 15 which contacts are made a part of a rotary switch provided with a rotating brush 16, connected electrically with a source of energy by a wire 17, and which brush is mounted upon a shaft 18 having a pulley 19 connected therewith and arranged to be rotated by any suitable means.

As shown in Figs. 1 and 2 the filaments 11 are grouped in circular arrangement, and as clearly shown in Fig. 3 the filaments bear such electrical relation with the contacts 15 as to cause energization and luminosity; first, of the filament 11 designated A in Fig. 2; then the filament 13 diametrically opposite the filament A; then the filament C and then D, thereby causing the lamp to shed a light of uniform intensity in all directions.

in my drawings 1 show a lamp in which there are fourteen of the filaments, but obviously any number of filaments may be employed without departing from the spirit of my invention. The practical operation of the lamp is substantially as follows:

With energy flowing over the wire 17 through the shaft 18 of the rotary switch, and the arm 16 thereof to one of the contacts 15 through the corresponding conductor 12 to a filament 11, through the spider 10, through the wire 9 to the socket 13 and thence through the wire 14. to the source, and assuming the shaft 18 to be rotated it will be obvious that the duration of the energization and luminosity of the filaments is for a period of time, the brush 16 is in engagement with. a contact and it is to be understood that the speed of rotation of the brush is such as to energize a filament to the extent of luminosity and then immediately break the circuit.

This same filament of the group is then permitted to remain unenergized until all of the remaining filaments of the group of the wires 12 extends to a contact have been energized, during which time, of course, the said filament while unenergized continues to be luminous, but with gradually decreasing intensity practically to the time of its second or succeeding energization.

By this then, it will be understood that when the filament A is in circuit, it will have a maximum intensity ofl'uminosity for a period of time during the movement of the brush over its contact. The next succeeding contact is then engaged by the brush to energize the-filament B which is diametrically opposite the filament A. The next succeeding contact is then engaged by the brush to energize the filament C which is separated from filaments A and B by an angle of ninety degrees and the next succeeding contact is then engaged by the brush to energize the filament D which is dian'letrically opposite the filament G, the remaining contacts being the same relative arrangement with each other in order to produce luminosity of uniform intensity in all directions from the lamp.

By reason of the number of filaments and the relatively short interval between the energizations of the filaments in the order just described, it will be apparent that the flow of energy is inconstant, hence there will be a saving in current consumption in I claini as new therein, and desire to secure by Letters Patentis In combination with a single source of light, having a number of devices for translating electrical energy into light, a switch mechanically disconnected from the source of light, and arranged for continuous movement, and having a contact for each translating device of the source'of light, and a circuit including said translating devices, said switch and a source of electrical energy whereby each translating device may be momentarily energized in its turn to produce light during which time the remaining translating devices will be deenergized and cooled.

In testimony whereof I have signed my name to this specification in presence of two subscribing witnesses.

7 WILLIAM L. BARNARD. Witnesses R'G. ORwIe, M. E. KLEE. 

